1. Field of the Invention
The invention generally relates to a printing press having a device for correcting the register of a flexible printing plate on a plate cylinder. More specifically, the present invention relates to a device for pivoting flexible printing plates on a plate cylinder of a rotary printing machine. In essence, a device for pivoting a printing plate can have clamping/tensioning bars for mounting and clamping both plate ends of the printing plate, articulated levers pivot-mounted on the cylinder body and articulatingly connected to the clamping bars so that both clamping bars are adjustable with respect to each other, and control apparatus for turning, or pivoting, the printing plate on the plate cylinder in order to correct the register.
2. Background Information
One type of known device of the type described above is disclosed by German Patent Application No. 36 04 209 A1, which corresponds to U.S. Pat. No. 4,785,736. With the disclosed device, it is possible to cock the printing plate on the plate cylinder in order to correct the register. In general, the registers which are often corrected in printing presses include: "circumferential"--up and down on a printed page; "lateral"--side to side on a printed page; and "diagonal"--moving the top and bottom in opposite lateral directions. In general, such register corrections are necessary with multi-color printing machines, wherein each color is typically applied by a different plate, and as such, the plates essentially all need to be aligned with as much precision as possible to produce the highest possible quality printed image. Thus, such a machine can make it possible to compensate for photocopying errors, mounting errors and other types of errors which might cause the printed image to turn on the printing plate. Such a device can essentially simultaneously effect a circumferential/lateral correction of the printed image with respect to the reproduction of the printed image. However, the known embodiment provides a complicated construction which, in particular, when using small sheet-fed printing machines, leads to an increase in price, which is not appropriate.